The long term objective is to increase knowledge about basic psychobiological processes in storage and retrieval of information. The specific aims of identifying, assessing, and delineating various transformations of memory are addressed in four major areas of research: 1) Analysis of variables controlling anterograde amnesia, which is a frequent type of memory pathology in humans. Whether fever states and other common disruptions of homeostasis can act as sources of anterograde memory loss also will be determined. 2) Examination of the role of distinctive contexts during acquisition and testing in alleviating ontogenetic forgetting (infantile amnesia). These studies will investigate the necessary conditions for the alleviation effect, and explore the possibility that memory loss from other sources can be reduced by this type of manipulation. 3) Investigation of the modulation of old information which has been reactivated (retrieved). The nature of the change in hedonic value produced by a counterconditioning of memory treatment will be examined. This topic is important not only for understandng malleability of memory but also for potentially clarifying processes which presumably underlie clinical therapies such as desensitization. 4) Assessment of forgetting of stimulus attributes, a relatively neglected aspect of memory phenomena. In addition, this work will evaluate the implication that forgetting of stimulus characteristics permits increased interference and thus impaired retrieval of the target response.